24-hour direct-reading clock



July 21, 1953 E. J. UHUG ETAL 2,645,896

TwENTY-FoUR-HOUR DIRECT-READING cLocK Filed .Junee, 1952 4 sheets-sheet1 n .m a m .5 |m Mm my, N EN. ML JR. c n 1m 1w .vw. 1w n n, ww F. o Nw n.Q J d Nm Mw ww Q mw. w mw wm E NNNm .c m wm Sn MN n Sv l n www. ...S SQ h S. NN Q H! 1V/WQ July 21, 1953 E. J. UHLIGv ET AL 2,645,896

TWENTY-FOUR-HQUR DIRECT-READING CLOCK Filed June 6, 1952 4 Sheets-Sheet2 /TTORNEY July 2 1, 1953 E. J. UHLIG ET AL 2,645,896

TWENTY-FOUR-HOUR DIRECT-READING CLOCK Filed June e, 1952 i 4sheets-sheet s INVENTORS TTOR NE Y o 3'6 7'2 ls |44 |`ao ais 252 za :'24seo July 21, 1953 E. J. UHLIG ET A1.

TWENTY-FOUR-HOUR DIRECT-READING CLOCK Filed June 6, 1952 70, i9,- 48,se, z2,

O O O O 00 7V o o5 2 2 'lg i 3 3 2O 2Y 4 2. 4 25 560# 5 3 5 3o 6 6 35 74 7 2g 8 5 a 50 9 9k 55` y 4 Sheets-Sheetl 4 i uw * 13g-ff NVENTOR`TI'ORNEY Patented July 21,v 1953 h 2,645,896

' UNITED YSTA??E.S .PATENT 0F FICE v 1 2,645,896r e 2li-HOURDinner-READING CLOCK Erie J. Uhligiiaaaonneights, ma John RQLewis,

Collingswood, N. J., assignorsvtoWickes Engineering and ConstructionCompany, Camden, l NN. '.I.,. a corporation of New Jersey,Appiiatiossons 6,1952, seriaiNdzsarz e fs, Claudis.l (oms-'125) `Thisinvention relates to direct-reading clocks It is av further object toprovideva clock wherein -or the like, and moreparticularly ltodirectrreadthe hours and minutes drums may be reset ining clockswhich;'indicate.,ti me on,y a'- 2l-hour dependently without anypossibility of the drums basis. y y v i getting-outer propertime-indicating synchro- ,t Drum-typedirectfreading-iclocksV operatingonU nism.`

a 12-hour cyclefare-well known in the art..:Such Other `objects andnovel features of the con- `clocks normally have an jhoursfdrum with the.struction and arrangement of parts comprising numbers 0 .through 12thereon, altens of minutes this improved clock will be apparent as thede'- drum with theUnumbers-O throughi5 .thereon,2 scription of theinvention progresses. v.minutes ldrum with the .numbers, 0through 9 1U fAccording to the. present invention, separate thereon, andaf'secondsdrumwith indiciafor number drums are used forl the tens ofhours, lnumbers, 0 0 throughathereon. The seconds hours-tens of minutes,minutes and seconds. drum is driven, through appropriate gearing, byr,The seconds drum is rotated at a constant speed va synchronous motor;landthe minutes, tens of of one revolution per minute by a clock motor.minutes and,ghoursdrums are .coupled back to I Geneva-movementmechanisms are interposed the seconds drumrfthrough Geneva-movementbetween the five drums so that all drums except mechanisms lso thatthey' move intermittently in vthe driven seconds drum are rotated within- ,.proper.time-indicating.fashion. termittent motions intime-indicating fashion.

Ten, or even twelve numbers`v of adequate size. The hours drum, havingnumbers 0 through Aforrearsyreadingcan be put-arounda drum with- 9thereon, is advanced one number (thirty-six .out the drum -andclock casebecoming excessively degrees) every hour by a Geneva mechanism large andbulky. A ZLl-hourclock with the .num- Adriven from the tensof minutesdrum. Thetens of bers 0 through 2li arranged otra single drum hours drumhas numbers 0,0, l, l and2 distributed over 180, degrees of itsperipheral surface. A

Awould be so large and cumbersome-esto ,be `imy Y Geneva mechanismdriven from the hours drum practical formost applications.- l I As .analternativetohaving a-singlefhours ladvances the tens of hours drum onenumber drum'with numbers 0;through. ,24fthereon,.sepa (thirty-sixdegrees) every five hours. There- .rate h ours and tens ofahoursdrumsmay. be con'- fore, the rst number 0 onthe tens of hours drumsidered. The Iproblem immediatelyencountered is visible for iive hourswhile numbers 0, 1, 2, 3 Yarisesfrom the factthat the. hours drum must30 and 4 on the hours drum appear in succession. contain tenY numbersbut. a 24 hour ycycle .is not The second number 0 on the tens of hours.drums evenly .divisible by ten. .h Thereforethe hours Iis visible;with-numbers 5, 6, "I, 8 and 9 on the ndrum must successively indicatethevdiscontinu- Ahours drum. The first number 1 on the tens of ousseries of numbers0, 1, 2, 3, 455, 6, 7; 8,39, .hours drum is visiblewith numbers 0 through 4 ,0, 1, 2, 3, 4, 5, 6 "I, 8,l 9, 0,1, 2,3,-:4and then 0 35 ofthe hours drum, and the secondV number 1 is duringone 24-hour cycle, .visible with numbers 5 through 9.v Then the num-While others have worked on 24hour directber 2 on the tens of fhoursdrum is visible for reading clocks, so=.far as we knowy no one has fourhours with the numbers 0, 1, 2 and 3 on the succeeded in completelysatisfying theneeds of hours drum. This brings the 'reading up to 23.thosein .the communications, transportation, 40 hours.V At the endofthe fourhour period dury.military and naval fields who prefer such a.timeing which-the 2 on the tens of hours drum is visi- DeCe. It istherefore a gnelloblect Of :the b1e,..the hours drum shifts to indicatenumber present invention to provide' a24hour direct- 4, .and the lockthen reads time 2400. At this reading @100k WhichCombine-S.gOOdjlBgblitywith y instant, `a transfer mechanism goes intoopera- COmlOaCtrleSS in physical size. 1.15 .tion whereby ar detent orlatch locks the tens of v It iS 230th??k Object t9 DI'OVde w24-hourclock hours and thehours drums together and bothare employing avmechanisnfl Tequlinga minimum rapidlyA rotated 216 degrees, byoverdriving .number of parts. l `means, through the blank portion of thetens of It is afurther object to provide a clock which hours drum andthenumbers 4, 5,6, 7, 8 and 9 is reliable, simple in construction andrelatively 5g of the hours drum. The clock then reads time inexpensiveto manufacture. f y 0000 for some seconds before changing to time It isa further object to provide a Clock wherein 0001. -The recyclingprocedure takes a m-atter of the four visible. numbers indicating.liours and Aseconds and can be made to occur when the clock minutes areof equal size andare equally'spaced indicates time l2359 if desired, -orat any other rso as to maximize readability. 55 suitable time.

taken on the line Figure 6 is a sectional vievv taken on the line 6 6 ofFig. 1.

Figure 'l is a sectional view taken on the line 'I 'I of Fig. 1.

Figure 8 is a sectional view taken on the line 8 8 of Fig. 7.

Figure 9 is a graphical representation of the motions of parts of themechanism which will be used in explaining the operation thereof.

Figure 10 is a representation of the distribution of numbers around thevarious drums.

Figure II is a front elevation showing the appearance of .2a-hourdirect-reading clock.

Referring now in greater detail to the drawings, wherein like parts inthe several views are given the same numeral, a frame I4 has journaledtherein a compound shaft consisting of a main shaft I5 and a concentricsleeve shaft I5, both shafts being freely rotatable relative to theframe and to each other. An auxiliary shaft Il is also journaled inframe I4 in parallel spaced relationship with the compound shaft. Aclock motor or synchronous gear motor I8 mounted on frame I4 has anoutput shaft I9 provided with a pinion for driving a seconds assembly.

The seconds assembly as a unit is freely rotatable on main shaft I5 andit comprises a gear Wheel 2I meshed with pinion 2D, a seconds drum 22with indicia thereon as represented in Fig. 10, and a Geneva driver 23having a drive pin 24 and a locking shoulder 25. Motor I8 drives theseconds assembly at the constant speed of one revolution per minute.Gear Wheel 2i drives gear 26 which is xed on auxiliary shaft I1 so thatshaft I'l also rotates at one revolution per minute for purposes whichwill become apparent as the description proceeds.

The Geneva driver 23 drives a Geneva star wheel 2S which is freelyrotatable on shaft I I and which has six drive slots 30 and six locksurfaces 3I, the construction being shown to advantage in Fig. 3. GenevaStar wheel 29 is coupled to gear Wheel 32 through a spring-loadedratchet 33, the teeth of the ratchet being arranged so that star wheel29 drives gear wheel 32, but the latter can be overdriven. Both arefreely rotatable on shaft I'I. Once in every complete rotation of theseconds assembly, pin 24 drives star wheel 29 and gear Wheel 32 sixtydegrees. This motion is imparted to gear wheel 35 to cause a thirty-sixdegree rotation of the latter, the reduction being due to the gearratio.

It will be understood that Geneva mechanisms are old in the art and thatthe present invention is not on Geneva mechanisms per se. Therefore, itwill not be necessary to describe herein the Geneva mechanism in greatdetail.

Gear wheel 32 intermittently drives a minutes assembly including gearwheel 35, minutes drum 36 with indicia thereon as shown in Fig. 1-0, anda Geneva driver 31 including drive pin 38. The

minutes assembly is fixed on shaft I5 as is the minutes set wheel 4U.When set Wheel 40 is used to set the minutes drum 36 to the proper time,the motion is not transmitted back to the seconds assembly by reason ofthe overriding action of ratchet 33.

Once during every revolution of minutes drum 36 and Geneva driver 31,drive pin 38 causes a thirty-six degree rotation of Geneva star Wheel42. Star wheel 42, as shown to advantage in Fig. 4, consists of a drivenwheel 43 with ten notches and a lock Wheel 44 having ten lock surfaces.The two-part construction with each part operative in a separate planeis employed because of the relatively large number of teeth needed. StarWheel 42 is directly coupled by shank 45 to gear Wheel 46; all as a unitare freely rotatable on shaft I1. Each thirty-six degree rotation ofgear wheel 46 causes a sixty degree rotation of gear Wheel 4T by reasonof the gear ratio.

Gear wheel 46 causes rotation of a tens of minutes assembly which, as aunit, is freely rotatable on main shaft I5 and which consists of a gearWheel 41, a tens of minutes drum 48 with indicia thereon as representedin Fig. 10, and a Geneva driver 49, with drive pin 50. Driver 49 drivesGeneva star wheel 53, shown to advantage in Fig. 5. Star wheel 53 hassix notches 54 and it is coupled to gear wheel 55 through spring-loadedratchet 56. Once during each rotation of the tens of minutes drum 48 anddriver 49, star wheel 53 and gear wheel 55 are made to rotate sixtydegrees, which in turn causes a thirty-six degree rotation of gear wheel58.

An hours assembly is fixed on sleeve shaft IB and it consists of gearWheel 58, hours drum 59 having indicia thereon as represented in Fig.10, and a Geneva driver 60 having two driver pins 6I and 62 disposed 180degrees apart. An hours set Wheel B3 is also fixed on sleeve shaft I6for setting the hours drum to the correct time. During the settingprocedure, ratchet 56 is overridden so that the motion is nottransmitted back to the tens of minutes drum 48.

A compound Geneva star wheel 64 and directly coupled gear wheel 65 arefreely rotatable as a unit on auxiliary shaft I'I and are rotatedthirty-six degrees once during every half revolution of hours drum 59and driver 60. Star wheel 64 is shown to advantage in Fig. 6; itconsists of a slotted driven disk 61 and a lock disk 68 having sixconcave lock surfaces. It will be noted that a portion 69 of theperiphery of lock disk 68 is without lock surfaces, for reasons whichwill be treated as the description proceeds.

A tens of hours assembly consisting of a tens of hours drum 'I0 withtens of hours numbers O, 0, 1, 1 and 2 thereon, a gear wheel 1I, and amutilated Geneva star Wheel I2 is freely rotatable as a unit on sleeveshaft I6. Gear wheel II is meshed with gear wheel 65 on auxiliary shaftI'I. Therefore, gear wheel "II, tens of hours drum 10, and mutilatedGeneva wheel I2 are driven thirty-six degrees every time the Genevamechanism 60, 64 operates.

A circular notched cam l5 is fixed on sleeve shaft I6 so that it ismaintained in a predetermined relationship with the hours drum 59, whichis also fixed on sleeve shaft I6. A stationary sector cam I6 having aninternal concave cam surface is mounted on frame I4 by means of supportsTI, TI. A Geneva driver is fixed on auxiliary shaft II and is providedwith six driver pins spaced thirty degrees apart. Five of the driverpins 8| are of a length to be operative '.erative in a plane betweenmutilated star wheel 12 and cam 15. Geneva driver 8U is rotated at theconstant speed of one revolution per minute by shaft i1 which is in turndriven by motor i8 through pinion 20, and gear wheels 2| and 26.

As shown to advantage in Figs. '1 and 8, mutilated star wheel 12 has veteeth 84 which are driven by the ve driver pins 8l. There is a sixthtooth 85 reciprocably mounted on mutilated wheel 12. The limits anddirection of reciprocation are determined by slots 86 and 91 in thereciprocable tooth 85 and pin 88 extending from mutilated wheel 12, andsleeve shaft I5. A cam follower pin 99 extends from one end ofreciprocable tooth 95 and rides on the surface of cam 15. A spring 9|mounted at 92 on mutilated star wheel 12 urges cam follower pin 90against the surface of cam 15. In the drawings, the reciprocable tooth95 is shown in one o'fits extreme positions wherein cam follower pin 9ois in the notch on cam 15. In this position, the reciprocable tooth 85extends out radially like xed teeth S4 on mutilated star wheel 12, andis in a position to be operated upon by elongated driver pin 92 ofGeneva driver 80.

The reciprocable tooth 85 is provided with a foot 94 which extends intothe plane of fixed cam 16. 94, prevents cam follower pin 99 from fallinginto the notch on cam 15 when the clockmechanism is in a position toindicate time 1200. Fixed cam 19 also serves in effecting a lifting ofcam follower pin 99 out of the notch on cam 15 to unlock drums 59 and 13following the recycling operation occurring at time 2400.

Fig. 10 illustrates the number indicia arranged around 360 degrees ofthe peripheral surfaces of the various drums. second drum 22 has numbersfor sixty'seconds counting by fives, the minutes drum has numbers 0through 9, the tens of minutes drum 48 has numbers 0 through 5, thehours drum 59 has numbers 0 through 9, and the tens of yhours drum 19has numbers 0, 0, l, 1 and 2. 'Ihe seconds drum 22 may have the numberson a colorcoded background with a separate color for each quarterminute. The numbers are evenly distributed around `all drums except thetens of '.1

hours drum 19, which has the numbers distributed around half of theperipheral surface. In Fig. 10, the numbers are arranged to moveupwardly past a window, whereas in the other iigures of the drawings thenumber vdrums move i.

downwardly past the Window. Either arrangement of the numbers may beused.

Fig. 11 illustrates the appearance of the clock when provided with amask 96 having windows through which the numbers on the disks arevisible.

The operation of the 24-hour direct-reading clock will now be describedand the chart of Fig. 9 will be used toexplain the operation of thetransfer means associated with the hours drum 59 and the tens of hoursdrum 19. Motor I8y drives the seconds drum 22 at the constant speed ofone revolution per minute. Once during every revolution of seconds drum22, minutes drum 36 is advanced thirty-six degrees or one- .l

tenth of a revolution, the motion being transmitted from Geneva driver23 through Geneva star wheel 29, ratchet coupling 33 and gear wheels32,95. Once during every revolution of minutes drum 36 the tens ofminutes drum 48vis advanced Fixed cam 16, when engaged by foot i' Itwill be noted that the j drum 59. y

mutilated star wheel 12, and drums i9 and 59,

sixty degrees or one-sixth of a revolution, the motion being transmittedfrom Geneva driver 31 `through Geneva star Vwheel 42, shank and gears4E, 41. Once during each revolution of the tens of minutes drum 48, thehours drum 59 is advanced thirty-six degrees or one-tenth of a yrevolution, the motion being transmitted from Geneva driver 49 throughGeneva star wheel 53, ratchet coupling 56 and gears 55, 58. Once duringeach half revolution of hours drum 59, the tens of hours drum 10 isrotated thirty-six degrees or one-tenth of a revolution, the motionbeing transmitted from Geneva driver 60 through Geneva star wheel 5d andgears 65, 1I. Drums 35, 48, 59 and 19 are normally stationary and areadvanced quickly by the Geneva mechanisms from a position where onenumber on the drum is visible to a position where the next higher numberis visible.

Drums 3B, L19, 59 and 10 are thus advanced in time-indicating fashionfrom time 0001 to time 2400. It will be noted that the tens of hoursdrum 19 is advanced every five hours from number 0, to number 0, tonumber. 1, to numberl and to number 2. The motion of the tens of hoursdrum 10 is illustrated by dotted line 91 in Fig. 9, the verticalportions indicating the periods of time when the drum is stationary andthe horizontal portions indicating the times at which Vthe drum isrotated to reveal the next number. The repeated numbers 0 and 1 aredistinguished in Fig. 9 by subscripts 1 and 2. The horizontal axis ofFig. 9 indicates angular relationship relative to a fixed point on frameI4.

The motion of the hours drum 59 is represented in Fig. 9 by the line 98,the vertical portions representing the hourly periods during which thedrum is stationary and the horizontal portions indicating the thirty-sixdegree rotational shifts made by the drum once per hour.r

Reciprocable tooth rotates with tens of hours drum 10 so the line 91 inFig. 9 also represents the motion of the reciprocable tooth B5. Simiilarly, notched cam 15 rotates with the hours drum 59, and its motion isrepresented by line 98 in Fig. 9. Wherever lines 91 and 99 intersect,the cam-'following pin 99 of reciprocable tooth 85 is in a position tobe urged by spring 9! into the notch on cam 15. It will be noted fromFig. 9 that there is a period of one hour between time 1200 and time1300 duringv which lines 91 and 99 intersect, indicating that pin 9o isin line with the notch in cam 15. However, reciprocable tooth 85 isprevented from shifting by reason of its foot 94 encountering theIstationary cam 16. The arrow 99 in Fig. 9 indicates the sector overwhich the stationary cam 15 is operative in this manner. Lines 91 and 98again intersect at the point designated E99 on Fig. This occurs at time2400 and the elements of the latching or transfer means are then in thepositions shown in. Figs. l, 7 and 8. As shown to advantage in Fig. '1,cam-following pin 99 has fallen into the notch on cam 15 allowingreciprocable tooth to extend radially into position where it may beoperated upon by elongated pin 92 of Geneva driver 99. Driver 89, beingiixed auxiliary shaft i1 is always driven at the constant uniform speedor? one revolution per minute. When the of reciprocable tooth 95 is inthe notch of cam l5, the tens of hours drum 19 and the hours drum 59 arelocked together, since tooth 85 is connected to tens of hours drum 'iiiand cam 15 is connected to hours Geneva driver then rapidly drivesthrough 215 degrees to a position Where numbers on both drums are inreading position. Drums l@ and 59 are overdriven relative to the tens ofminutes drum, the overdriving being possible because of the presence ofratchet coupling S between drums 5S and f1.3. When drums 'I6 and 5s arelocked and rotated, there is no interference between Geneva driver 5eand Geneva star Wheel Eff; this is because a. portion 59 or" the lockdisk t3 is out auf'ay. Pins 6l of Geneva driver 8S never engage teeth ofmutilated star Wheel 'F2 except following the engagement of elongatedpin 82 vwith reciprocable tooth 85 because between time 6061 and time2409 the teeth S1 do not extend into the circle of rotation or" pins 53.

As the locked drums l@ and 5S are quickly rotated from. positionsindicating numbers 24 through 5, -6, *7, 8, -9- to 00, reciprocabletooth 85 rotates with the drum until, at time 00 hours, the foot ortooth 85 eng .ges stationary cani 'i6 resuiting 'n cam-following pin Silbeing lifted out of t1I` Inotch in cam l5. Stationary cam i8 koe :s recminutes :irurL linurl. .l

I l" e ,L ,r

Shaft drinn t5 advancement of the tens of m iutes drum through theaction o the fs, mechanism 3'?, 42 between t .e No more than sii:revolutions of the minutes un are d to se drums and LES to indicationbetvf'een CO and 59 minutes. The rotation. of ininutes drinn does notreact baci; to the seconds drum 22 because ratchet between the dri 3overridden. An accurate setting ci seconos drum 2. is made by switchingthe Vloc-tri motor iB.

Hours drum 59 fixed by rotating knurled ai fixed on sleeve sh ierotation o hours drum 59 also results in the advancement of the itthrough the action or 6ft between the drums. lilo e i tions of hoursdrum are needed to set he two drums to any readingbetween 00 and 24hours. The rotation oi hours drum 55 is not transmitted baci: to tens ofminutes drum i3 by reason o ratchet 5t being overridden.

Ratchet 33 has ten teeth and minutes drum Z-l has ten number positions.Therefore, the resetting procedure cannot disturb the ne ssarysynchronous relationship between drums and Similarly, ratchet e6 has tenteeth and hours drum 59 has ten number positions so as to maintainsynchronism betvf'een drums .S and 59.

t will be understood by those skilled in the art hat a construction maybe employed wherein the tens of hours drum carries solely the number o,1 and 2 and the drum is advanced at ten-hour intervals rather thanfive-hour intervals.

Other variations and modifications of the parts and or" their positionsand arrangements may be r.1 de by those skilled in the art Withoutdepartiroin the nature of the invention Within the more than thre 111gscope of vwhat is hereinafter claimed.

What is claimed is:

l. in a 2a-hour direct-reading clock or the like, t ie combinationcomprising an hours drum having the numbers 0 through 9 thereon, meansoperatlve once per hour to advance said drum one number, a tens or"hours drum having the numbers 0, i and 2 thereon, a Geneva mechanismoperatively interposed between said drums to advance said tens of hoursdrum at least once during every complete cycle or the hours drum, andtransfer means operative responsively to a prede tei-mined relativeposition of said hours and tens of hours drums to lock them together andquickly rotate them substantially 216 degrees.

2. A 24-hour direct-reading clock comprising an hours drum and a tensci" hours drum, means lor driving the hours drum, Geneva movement meansoperatively connecting the tens or" hours drum with the hours d n,detent opera f to lock the hours and t Ls drums from elif-ot saidmovement oi the locked hours and tens of hours drums.

3. A 24-hour direct-reading clocl; or the like, comprising an hours drumwith the numbers 0-9 evenly spaced thereabout, a tens of hours drum withthe numbers O, 0, l, l and 2 spaced over 180 degrees of the drum, meansfor driving the hours drum, Geneva movement means operative after eachhalf revolution of the hoursI drum to turn the tens of hours drum 36degrees, a detent operative every 2li hours to lock the hours and tensof hours drums together, and overdriving means operative responsively tosaid detent to rotate locked drums substantially 216 degrees.

e. In a 2e-hour direct-reading clock or the like, the combination or" anhours drum having the numbers 0 through 9 evenly spaced thereabout,means for advancing said drum 36 degrees every hour, and overdrivingmeans opera-tive after every 864 degrees of rotation of said drum toquickly rotate the drum 216 degrees.

5. In a .2i-hour direct-reading clock. or the the combination of anhours drum having the numbers 0 through 9 thereon, a window7 disposed.to reveal one oi said numbers at a time for viewing, means operativeevery hour for advancing said drum to reveal the next successive number,and overdriving means operative every 24 hours to quiclly advance saiddrum through the positions revealing numbers through 9.

6. A 24-hour direct-reading clock comprising individual indicating drumsfor tens of hours, hours, tens of minutes, minutes, and seconds, adriving motor geared to the seconds drum, Geneva mechanisms coupling thedrums so that they rotate in time-indicating fashion, latch meansoperative every third time the number 4 on the hours drum appears in theviewing position, and overdriving means deriving power from said drivingmotor operative cooperatively with said latch .means to quiirly rotatethe hours drum to a position Where the number zero is visible.

7. A 24-hour direct-reading clock comprising individual indicating drumsfor tens of hours, hours, tens of minutes, minutes, and seconds, adriving motor geared to said seconds drum, Geneva mechanisms couplingthe drums so that they rotate in time-indicating fashion, latch meansconnected with the hours drum operative every 24 hours, and overdrivingmeans deriving power from said driving motor operative cooperativelywith said latch means to quickly rotate the hours drum substantially 216degrees.

8. A 2li-hour direct-reading clock comprising individual indicatingdrums for tens of hours, hours, tens of minutes and minutes, numbers (lthrough 9 distributed around the periphery of said hours drum, drivingmeans including Geneva mechanisms for driving said drums intime-indicating fashion, latch means connected With the hours drumoperative every third time the number 4 on the hours drum reaches apredetermined position, and overdriving means operative responsively tosaid latch means to quickly rotate the hours drum until the number zeroon the drum reaches said predetermined position.

ERIC J. UHLIG. JOHN R. LEWIS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Terrell May 8, 1906 Holzner June 20, 1944 Deane Aug. 8, 1944Bush May 13, 1952

